audio-entropyd

audio-entropyd feeds the /dev/random device with entropy data read from an audio device. The audio data is not copied as is, but first 'de-biased' and analyzed to determine how many bits of entropy are in it. This program is useful for systems doing many cryptographic tasks like VPN endpoints or GPG clients; it helps prevent the /dev/random device from being depleted and blocking reads.

Release Notes: The sample-rate was lowered. The mixer-code was
removed. The daemonise-function was changed to use
daemon(...). The hashing-code was removed. Code
that determines the amount of entropy in a buffer
of data was added. The method of entropy-gathering
was rewritten. Some code has been added to remove
bias in the data.

Release Notes: This release lets the daemon wait until the kernel signals that the lower threshold in /proc/sys/kernel/random/write_wakeup_threshold (number of bits) has been reached, then starts adding until the value of /proc/sys/kernel/random/poolsize (in bytes) has been reached. After a timeout, some entropy is still added (i.e.--wait), just like in version 0.0.0. The signals don't cause problems anymore with reading audio from the sound card.

TODO: Circuit for white noise generator, powered by keyboard socket
Does anyone have a diagram for a circuit like mentioned in the TODO file?
I.e.: Circuit for white noise generator, powered by keyboard socket.